磷脂酶A_2阻断剂对缺血-再灌注损伤诱导细胞凋亡和坏死的影响

Effect of phospholipase A_2 inhibitors on ischemiareperfusion injury induced apoptosis and necrosis

目的：探讨磷脂酶Ａ２ 活性对缺血 再灌注损伤过程中主要免疫细胞凋亡和坏死的影响。方法：采用ＤＮＡ 凝胶电泳、电镜、光镜以及流式细胞分析（ＦＡＣＳ）等方法测定了大鼠肠缺血 再灌注损伤后外周血中性粒细胞、脾脏细胞和胸腺细胞细胞凋亡和坏死情况及外源性磷脂酶Ａ２ 阻断剂对其的影响。结果：大鼠经小肠前动脉夹闭６０分钟、再灌注２７０ 分钟后，上述细胞出现程度不同的凋亡或坏死，ＤＮＡ电泳出现“梯形”或弥散状“拖尾”。缺血后再灌注前使用磷脂酶Ａ２ 阻断剂４ 溴苯甲酰乙烷（ｐ ＢＰＢ）、氯喹、血小板活化因子（ＰＡＦ）受体阻断剂ＳＲ２７４１７（５ ｍ ｇ／ｋｇ）后，对中性粒细胞的ＤＮＡ降解、坏死有显著的抑制作用，而对胸腺和脾细胞ＤＮＡ 降解、细胞凋亡没有明显的影响。结论：肠缺血 再灌注损伤可诱导外周血中性粒细胞、脾脏细胞和胸腺细胞细胞凋亡和坏死，在整体实验中阻断磷脂酶Ａ２

Objective: To investigate the effect of phospholipase A 2(PLA 2) activity on apoptosis and necrosis of neutrophils,thymocytes and splenic cells during ischemiareperfusion (IR) injury.Methods:The apoptosis and necrosis of above cells after IR injury were examined by DNA agarose electrophoresis,fluorescence activated cell sorting,electronic and light microscope.Results:It showed that apoptosis or necrosis occurred in all above cells as manifested by a DNA ladder or diffused DNA tail in agarose electrophoresis,after 60 minutes of superior mesenteric artery occlusion followed by 270 minutes reperfusion.The apoptosis or necrosis of neutrophils could be significantly inhibited by the treatment of bromophanacyl bromide (pBPB) and chloroquine,two different PLA 2 inhibitors,or platelet activating factor receptor antagonist SR27417 (5 mg/kg),but these agents did no show obvious effect on thymocytes and splenic cells after IR injury.Conclusions:These results indicate that intestinal IR injury could induce apoptosis or necrosis of thymocytes,splenic cells and neutrophils.Inhibition of PLA 2 in vivo could notably decrease the necrosis of neutrophils.